DUFF CO operating as a sole owner is licensed in California under CSLB number 742203. The license was first issued in 1997, putting the business at 29 years on the active CSLB roster. It carries 2 CSLB classifications: A General Engineering Contractor and C-31 Construction Zone Traffic Control Contractor. Records show an active surety bond on file with AMERICAN CONTRACTORS INDEMNITY COMPANY and an exempt workers' compensation status (no employees on payroll). The business is based in IONE, in Amador County, California.